Provided is a degradation diagnostic device, which is configured to perform a diagnosis for degradation of a compressor including a compression mechanism unit to be driven along with a rotational motion of a rotary shaft, and a shell, which is configured to form an outer casing. The degradation diagnostic device includes a vibration detection device to be fixed onto an outer wall of the shell at a position at which the compression mechanism unit is located. The vibration detection device includes: a vibration sensor, which is configured to detect vibration of the compressor; a sensor holding unit including the vibration sensor; a base portion to which the sensor holding unit is connected; and a plurality of projecting portions, which are formed on a surface of the base portion on a side opposite to the sensor holding unit and to be brought into contact with the outer wall.

Disclosed is a screw compressor (100), comprising a screw compressor housing (101), a discharge cavity (113), at least one silencing channel, and at least one adjustment piston, wherein the discharge cavity (113) is defined by at least one part of the screw compressor housing (101); the at least one part of the screw compressor housing (101) defining the discharge cavity (113) forms a wall of the discharge cavity (113); at least one hole is provided in the wall of the discharge cavity (113); the at least one adjustment piston can be inserted into the at least one hole and move therein; the at least one silencing channel is formed by the at least one hole and the at least one adjustment piston, and the at least one silencing channel is in fluid communication with the discharge cavity (113); and the position of the at least one adjustment piston in the at least one hole determines the silencing length of the at least one silencing channel.

Disclosed is a screw compressor (100), comprising a screw compressor housing (101), a discharge cavity (113), at least one silencing channel, and at least one adjustment piston, wherein the discharge cavity (113) is defined by at least one part of the screw compressor housing (101); the at least one part of the screw compressor housing (101) defining the discharge cavity (113) forms a wall of the discharge cavity (113); at least one hole is provided in the wall of the discharge cavity (113); the at least one adjustment piston can be inserted into the at least one hole and move therein; the at least one silencing channel is formed by the at least one hole and the at least one adjustment piston, and the at least one silencing channel is in fluid communication with the discharge cavity (113); and the position of the at least one adjustment piston in the at least one hole determines the silencing length of the at least one silencing channel.

A rotary compressor, comprising: a housing, comprising a lubricant oil storage part for containing lubricating oil; a compression mechanism disposed in the housing; a driving mechanism driving the compression mechanism, the driving mechanism comprising a rotation shaft, through-holes extending along the axial direction of the rotating shaft are disposed inside the rotating shaft, and the rotation shaft is in fluid connection with the lubricating oil storage part via the through-holes; and an oil level sensor in fluid connection with the through-holes inside the rotation shaft via a pressurized collection channel. Also disclosed is a rotation mechanism, comprising an oil level sensor in fluid connection with the through-holes inside the rotation shaft via the pressurized collection channel. Accurate and reliable detection of the lubricating oil in a compressor can be done using the pressurized collection channel and the oil level sensor, thus greatly saving cost and improving compressor reliability.

A rotary compressor, comprising: a housing, comprising a lubricant oil storage part for containing lubricating oil; a compression mechanism disposed in the housing; a driving mechanism driving the compression mechanism, the driving mechanism comprising a rotation shaft, through-holes extending along the axial direction of the rotating shaft are disposed inside the rotating shaft, and the rotation shaft is in fluid connection with the lubricating oil storage part via the through-holes; and an oil level sensor in fluid connection with the through-holes inside the rotation shaft via a pressurized collection channel. Also disclosed is a rotation mechanism, comprising an oil level sensor in fluid connection with the through-holes inside the rotation shaft via the pressurized collection channel. Accurate and reliable detection of the lubricating oil in a compressor can be done using the pressurized collection channel and the oil level sensor, thus greatly saving cost and improving compressor reliability.

A delivery device for delivering a medium in a vehicle and for limiting a system pressure of the delivery device includes a vehicle pump, which is driven by an electric motor. The electric motor is controlled by a controller, the controller being configured to detect an actual rotational speed of the electric motor and an actual operating current of the electric motor. If the actual operating current of the electric motor exceeds a predefined operating current limit value, the controller is configured to generate a first signal relating to a system pressure being exceeded. The predefined operating current limit value is dependent on the actual rotational speed of the electric motor.

An automatic oil level retention system for a compressor and a method for controlling a same, including: a normal oil return mode and an auxiliary oil return mode. When a lubricating oil liquid level monitored by a liquid level detection unit in real time is above a required liquid level height, the system initiates only the normal oil return mode; and when the lubricating oil liquid level monitored by the liquid level detection unit in real time is below the required liquid level height, the system initiates the auxiliary oil return mode, and the auxiliary oil return mode is closed and the normal oil return mode is initiated after the lubricating oil liquid level monitored in real time is lifted above the required liquid level height.

A method including: determining a cooling value; and comparing the cooling value to an activation point of a lead compressor. The lead compressor is in a tandem set of scroll compressors of a cooling system. The tandem set of compressors comprises a lag compressor. The method further includes: activating the lead compressor when the cooling value is greater than the activation point; activating the lag compressor subsequent to activating the lead compressor; and determining whether conditions exist including: an alarm associated with the lag compressor being generated, and the lead compressor being deactivated. The method further includes deactivating the lag compressor when at least one of the conditions exists in the cooling system.

A method including: determining a cooling value; and comparing the cooling value to an activation point of a lead compressor. The lead compressor is in a tandem set of scroll compressors of a cooling system. The tandem set of compressors comprises a lag compressor. The method further includes: activating the lead compressor when the cooling value is greater than the activation point; activating the lag compressor subsequent to activating the lead compressor; and determining whether conditions exist including: an alarm associated with the lag compressor being generated, and the lead compressor being deactivated. The method further includes deactivating the lag compressor when at least one of the conditions exists in the cooling system.

A scroll compressor is provided that may include an orbiting scroll having an orbiting wrap, and which performs an orbiting motion; and a fixed scroll having a fixed wrap to form a compression chamber including a suction chamber, an intermediate pressure chamber, and a discharge chamber, by being engaged with the orbiting wrap. In a state in which the orbiting scroll and the fixed scroll are concentric with each other, when a distance between the orbiting wrap and the fixed wrap is defined as an orbiting radius, there exists an offset section having an interval larger than the orbiting radius, between a side surface of the orbiting wrap and a side surface of the fixed wrap which faces the orbiting wrap. With such a configuration, even if the fixed scroll or the orbiting scroll is transformed due to thermal expansion, interference between the fixed wrap and the orbiting wrap at a portion having a large transformation amount may be prevented. This may prevent a frictional loss or abrasion between the fixed wrap and the orbiting wrap. Further, this may restrict or minimize a gap between the fixed wrap and the orbiting wrap at an opposite side to the suction chamber, resulting in enhanced compression efficiency.